Here is code I use to find an image and fill in the path for a record:
Private Sub Btn_FindImage_Click()
Dim asFile As String
Dim afDialog As Office.FileDialog
Set afDialog = Application.FileDialog(msoFileDialogFilePicker)
.Title = "Select Image"
.InitialView = msoFileDialogViewLargeIcons
If .Show = True Then
asFile = Trim(afDialog.SelectedItems(1))
Me.ImageFile = asFile
Me.Img.Picture = asFile
MsgBox "File selection cancelled by user"
in the code I'm not limiting the file type because some people like scanning an image into a .PDF file for some strange reason. This code is called from a button. In your case you'd want to cancel saving if they don't actually choose an image file for one of your child records.
I don't have examples of the more elaborate methods, but both rely on copying the file. You would use the basic code above to identify the file and use something like CopyFile
to copy from your users selected name to a directory and name you generate.